Clin Exp Dermatol. 1990 Jul; 15(4): 277-81.

Reduced serum vitamin B12 levels during oral cyproterone-acetate and ethinyl-oestradiol therapy in women with diffuse androgen-dependent alopecia.

Ramsay ID, Rushton DH.

Department of Endocrinology, North Middlesex Hospital, London, UK.

In a group of healthy, non-vegetarian females currently being treated for diffuse androgen-dependent alopecia with 50 or 100 mg of oral cyproterone acetate for 11 days and 30 or 40 micrograms of ethinyl oestradiol for 20 days of the menstrual cycle, significant decreases in mean serum vitamin B12 (P less than 0.0001), haemoglobin (P less than 0.003) and haematocrit (P less than 0.004) values, were observed after 6 months. Serum folic acid, red-cell folate and mean cell volume remained unchanged within the normal range during this time. All patients responded to oral cyanocobalamin, or intramuscular injections of hydroxocobalamin. In patients with baseline serum vitamin B12 levels below 350 ng/l, we would suggest prophylactic cyanocobalamin concurrent with cyproterone-acetate-ethinyl-oestradiol (CPA EE2) therapy. Studies involving other dose regimens of CPA EE2 (Dianette) or cyproterone acetate alone (Androcur, Cyprostat), may require evaluation of the vitamin B12 status if treatment is to be given for periods of longer than 3 months.